Certain precious metals, such as in particular platinum group metals, gold and silver, despite their excellent chemical stability, are only suitable for a limited number of applications, since their mechanical properties are unsatisfactory. One possible way of improving the mechanical properties, such as the strength at elevated temperatures, is dispersoid-strengthening, which is also known as “dispersion-strengthening”. In the materials obtained, the improvement in the mechanical properties is based on the combination of the precious metal with non-metallic particles (the dispersoids) finely distributed therein, which allow the structured matrix to be stabilized. The structure of the matrix is obtained by deformation during the production of the precursor material.
There are a range of known processes which allow dispersion-strengthened materials to be produced. One of the earliest processes was the powder metallurgical method, in which dispersion-strengthened materials were produced by mixing metal powders with finely distributed refractory particles and then compacting the mixture. Further processes are spray processes, such as the method described in GB-B 1 280 815, and internal oxidation, which is disclosed, for example, in DE-A 178 30 74.
However, these known processes have the drawback of being complicated and expensive. Furthermore, they require the use of elevated temperatures or controlled working atmospheres. Consequently, there is a demand for a process which can produce dispersoid-strengthened materials in a simple and inexpensive way.